Charles Walsh: Beware of dangers from Vibrio bacteria

Charles Walsh

Updated 11:50 pm, Saturday, March 16, 2013

What better way to spend a summer day than wading into ankle-deep water with a pail and shovel to dig a big mess of tasty Connecticut clams? Pulling a half-a-bushel of sweet bivalve mollusks out of the mud can be a lot of work, but the rewards -- be they steamed, stuffed or fried -- are so worth the effort.

Now, like so many other fun activities once taken for granted, recreational clamming comes with a warning label: "Beware, eating improperly harvested or undercooked clams and oysters can be hazardous to your health."

Warming water temperatures in Long Island Sound cause elevated levels of a naturally occurring bacteria, called by the unpronounceable name of Vibrio parahaemolyticus. Exposure to Vibrio bacteria from eating undercooked or poorly stored shellfish can cause an intestinal disease called vibriosis. Fishermen also need to be aware of vibrio. Handling fish or working in water with elevated vibrio levels can cause cuts or open sores to become infected.

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Although there has never been a major outbreak of vibriosis in Connecticut, last summer, which DeRosia-Banik called "really warm," a few cases were reported in Norwalk and Darien resulting in temporary clamming closures in those areas.

Eating commercially harvested clam that are taken from deeper, colder water is safe, DeRosia-Banick said.

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Short castsSTOCKING UNDERWAY: With opening day of fishing season just a bit over a month away (Saturday, April 20), the state fish stocking program is finally well underway despite weather delays in February and early March. The Inland Fisheries Division of the Department of Energy and Environmental Protection (DEEP) says it will pour over 378,000 brook trout, brown trout, rainbow trout, and tiger trout into 102 lakes and ponds and 200 rivers and streams throughout the state before the bell sounds for Opening Day.HARVESTING REDUCTION REQUEST: More than 1000 Massachusetts anglers recently petitioned that state's legislature to request a 50 percent cut in both the commercial and recreational harvest of wild striped bass for the 2013 season. Citing a 90 percent drop in he recreational striper catch since 2006, Dean Clark, chairman of the Massachusetts chapters of Striper Forever, said "the great majority" of stripers migrate to the state waters from Chesapeake Bay (as they do to Connecticut), but there has been only one good spawning year in the Bay since 2006. The petition urged the lawmaker to act quickly on the catch reduction lest the striped bass go the way of the cod, which, driven by drastically low population estimates, will in May see a 77 percent cut in the commercial catch in the Gulf of Maine.-- CHARLES WALSH

• Harvest only from areas for which you have a permit and are open.

• Harvest as soon as possible after the tide goes out so that flats have been exposed for as little time as possible.

• Keep shellfish submerged until you leave the harvest area, and keep shellfish shaded until placed on ice or into refrigeration.

• Do not harvest oysters that have been exposed to direct sunlight for more than two hours.

• Place shellfish on ice or under refrigeration at less than 45°F immediately after harvest.

• Never leave shellfish in a car unless they are on ice in a cooler.

• Thoroughly cook shellfish. Internal temperature must reach 145°F for 15 seconds. Thorough cooking destroys Vibrio bacteria but barbecuing oysters or steaming clams just until they open will not inactivate the bacteria.

The symptoms of vibriosis include diarrhea, stomach cramps, nausea, vomiting, headache, fever and chills. Symptoms usually appear 12 to 24 hours after eating infected shellfish, and can last two to seven days. Vibriosis can be life-threatening for immune-compromised people or those with chronic liver disease. Also at greater risk are people who regularly take antacids, heart or diabetes medication, or who have had antibiotic or cancer treatments recently.